Why didn't you just ask us about this? Some of us have been doing this for quite some time. In fact, you've lost out on more than five years because if you'd been doing non-deductable TIRAs for a long time, you'd have been able to convert the whole thing to a Roth the first year it became possible. You'd have taken a tax hit on the earnings/growth of the account earned in that period but you would have been able to convert your original contribution without a tax hit because you never took a deduction on it in the first place.
Thanks, VinTek, you're right that I should have asked earlier and really missed out for not doing so. I completely lost those years, though, because I thought I could only contribute to my 401(k), and now I can't go back and take advantage of the IRA/Roth IRA, too. At least I caught 2012 in time, so it was actually four years that I skipped using any IRA vehicle. (Not that I lost the money itself, but just that it's limited to growth in taxable accounts only now.) Your post is a good reminder to actively seek the wisdom of the many people on the forum who have more years of experience and success! I enjoy reading people's questions and advice, but sometimes I'm shy to ask my own questions.